Improvement in rotary valves



0Q SNOWHILL & J n. sowu.v

improvement in R-btary Valves.

NO. 121,677; Patgnted Dec-5,187L.

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I MVFWL/ a UNITED STATES PATENT OFFICE.

DANIEL SNOWHILL AND JOHN D. BOWN, OF SPOTTSWOOD, NEW JERSEY.

IMPROVEMENT lN ROTARY VALVES.

Specification forming part of Letters Patent No. 121,677, dated December5, 1871.

To all whom it may concern:

Be it known that we, DANIEL SNowHILL and JOHN D. BoWN, of Spottswood, inthe county of Middlesex and State of New Jersey, have invented a new andImproved Rock- Valve for Steam- Uhests; and we do hereby declare thatthe following is a full, clear, and exact description thereof, whichwill enable others skilled in the art to make and use the same,reference being had to the accompanying drawing forming a part of thisspecification.

The drawing represents a vertical transverse section of our improvedrock-valve in a cylindrical steam-chest.

This invention relates to a new form of valve within a steam-chest, andhas for its object to reduce friction and simplify the operation of thevalve. The invention consists in the use of an oscillating, cylindrical,or slightlyconical valve, containing cross-slots for conveying the steamfrom the top of a chest to the ports, and a cavity for the exhaust. Inthis manner a simple valve is produced, and the steam-chest, as such,actually dispensed with, the steam passing from the pipe directly to andthrough the valve. This, it is evident, is the simplest means ofremoving the steam-pressure from the top of the valvethat is, having nosteam upon it.

In the drawing, A represents a steam-cylinder of suitable kind, havingthe steam-ports a and b that lead to a cylindrical or somewhat conicalsteam-chest or receptacle, 0, for the valve B.

This valve is of cylindrical or slightly-conical shape, and fits thechamber 0 so as to fill it entirely. The chamber 0 connects at its crownwith the steam-pipe d. The valve is slotted at e and f, the slotsextending clear across, as shown. They serve, respectively, to supplythe ports a b alternately with steam from the pipe (I. A cavity, g, inthe lower side of the valve connects the ports alternately with theexhaust-pipe h.

By a suitable link-motion the valve is rocked in order to open the portsin proper succession. This operation will be easily understood and neednot be further described.

We are aware that the Davis valve resembles ours in appearance to someextent; but he has and requires an extra steam-chest, which we dispensewith; being hollow at the center it has the same pressure as aslide-valve, which is an objection removed by ours; and our valve andchest being in one piece are more easily made and more durable.

Having described our invention, what we claim as new, and desire tosecure by Letters Patent, 1s

The cylinder 0 having the steamchest cast therewith, and provided withsteam passages d a b h, in combination with valve B having ports efg,all constructed and arranged substantially as and for the purposespecified.

DANIEL SNOVVHILL. JOHN D. B()\VN.

Witnesses:

J OHN L. APPLEBY, MERRELL MUNDY. (152)

